Burner and its operation



Oct. 24, 1967 Filed March 8, 1965 5 Sheets-Sheet 1 INVENTORS MILANMOMCHILOVICH ATTORNEY WALLACE F. RHODES a Oct. 24, 1967. M. MOMCHILOVICHET AL 3,348,598

BURNER AND ITS OPERATION 5 Sheets-Sheet 2 Filed March a, 1965 INVENTORS'WALLACE F. RHODES a MILAN MOMCHILOVICH FIG. 5

ATTORNEY 1967 M. MOMCHILOVICH ET AL BURNER AND ITS OPERATION 5Sheets-Sheet 3 INVENTORS WALLACE F. RHODES a v MILAN MOMCHILOVICH BYFiled March 8, 1965 ATTORNEY Oct. 24, 1967 M. MOMCHILOVICH ET AL BURNERAND ITS OPERATION 5 Sheets- SheeT; 4.

Filed March 8, 1965 WALLACE F RHODES a MILAN MOMCHILOVIC BY INVENTORS AT T ORNE Y Oct. 24, 1967 MOMCHILOVICH ET AL 3,348,598

BURNER AND ITS OPERATION Filed March 8, 1965 5 Sheets-Sheet s Q) LLINVENTORS LL WALLACE F. RHODES a MILAN MOMCHILOVICH BY ATTORNEY UnitedStates Patent 3,348,598 BURNER AND ITS OPERATION Milan Momchilovich,Akron, and Wallace F. Rhodes,

Stow, Ohio, assignors to The Falls Stamping and Weld- Filed Mar. 8,1965, Ser. No. 437,702 Claims. (Cl. 1584) This application is acontinuation-in-part of our Ser. No. 236,481 filed Nov. 9, 1962 nowabandoned.

This invention relates to an oil burner which includes a new nozzle andnew combustion chamber, etc. which include novel features ofconstiuction. The invention relates also to a new method of oilcombustion.

The burner is designed particularly for use in operations in which theburner is turned all of the way ON. Provisions are made for varying theoil and air supplied, between a higher or lower heat requirement. At thetime the burner is manfactured or when it is installed, the proper meansis selected for feeding just the required amount of oil and air throughthe nozzle, and this amount will be greater or less depending upon thefiring rate, i.e. the B.t.u. (British thermal unit) rating of theequipment in which the burner is installed.

The burner is particularly adapted for use in a dwelling, such as a homeor apartment, in which one or more furnaces, water heaters,incinerators, clothes driers, etc. are installed. Each is provided witha burner, and all of the burners are supplied with oil from a singlesource. For this purpose, a small reservoir for oil, equipped with aconstant-level device, is provided just below each burner nozzle, andoil is lifted from this constant-level device up into the burner by airsupplied from a single compressor provided with a manifold which feedsair to each burner through a different outlet under a given pressure.

Each burner functions only when air is supplied to it. The air draws theoil into the burner. The air supply for any one burner is always underthe same pressure, although the air may be supplied from the manifold tothe ing Company, Cuyahoga Falls, Ohio, a corporation of 0 differentburners under different pressures. On installation,

the oil burner is equipped to supply the amount of oil required for thatburner, and a larger or smaller number of openings are provided in theburner for admission 'of the equired amount of secondary air forcombustion of that amount of oil. The amount of oil'supplied to a burnerdepends upon the firing rate of the equipment in which it is installed.I

Pressure valveson the air manifold supply air through separate air linesto the different pieces of equipment at the required pressures which maybe different in each air line. For instance, identical burners, withproper adjustment at the time of installation, may provide air at 3pounds pressure per square inch to the burner in an incinerator whichuses 18 cubic centimeters of oil per minute to provide 35,000 B.t.u.(British thermal units) to the incinerator, and air at 4 pounds pressureper square inch to the burner in a furnace which uses 38 cubiccentimeters of oil per minute to provide 75,000 Btu. to the furnace. Thesystem is designed particularly for operation at low air pressures,usually less than ten pounds per square inch,

although a higher air pressure may be used. The burner may be used in acommercial installation, but is designed particularly for use in asystem in a dwelling, which may be a modification of the systemdescribed in US. Ser. No. 236,481 filed Nov. 9, 1962, by Momchilovichand Rhodes.

Oil and primary air are supplied to the burner nozzle. A whirling motionis imparted to this mixture within the nozzle. After leaving the nozzle,secondary air is added to the mixture, it is given a whirling motion,and passed over heated wires (preferably a stainless steel of high3,348,598 Patented Oct. 24, 1967 quality) and usually arranged as aseries of screens, to gasify the oil. The Wires are heated to red orwhile heat, i.e. about 1800 F. or greater. They break down any dropletsin the air-oil mixture and radiate infra-red rays which quickly heat themixture passing between the wires to a temperature at which the oil isbroken down and gasified. The resulting gaseous mixture is supplied to asupplement tal burner where it is burned. This supplemental burner maybe of any suitable construction.

It is desirable to provide a series of wires or screens in thecombustion chamber, and the oil and air may pass through these in onlyone direction; 'but it is preferable to mix secondary air with themixture after it has passed through the wires or screens in onedirection, and then pass the mixture back through the Wires or screensand there blend the gasified product with the gases in the combustionchamber and pass this from there to'the supplemental burner wherecomplete combustion takes, place.

No soot deposits form within the nozzle or combustion chamber, dueprimarily to the temperatures involved.

' The invention is further described in connection with the accompanyingdrawings, in which:

FIGURE 1 is a plan view of the burner;

FIGURE 2 is an enlarged section on the line 22 of FIGURE 1;

FIGURE 2A is an elevational detail on the line 2A-- 2A of FIGURE 2;

FIGURE 3 is a section on the line 33 of FIGURE 1;

FIGURE 4 is a section on the line 44 of FIGURE 2;

FIGURE 5 is a section on the line 5-5 of FIGURE 4;

FIGURE 5A is a section on line 5A.5A of FIG- URE 5;

FIGURE 6 is an exploded view of the burner;

FIGURE 7 is an enlarged ection through the nozzle; FIGURE 8 is a sectionon the line 88 of FIGURE 7;

FIGURE 9 is an exploded view of the nozzle; and FIGURES 10 and 11 aresections on the lines 1010 and 1111-of FIGURE 9, respectively.

Referring first to FIGURES 7 to 11, the nozzle 1 (FIG- URE 7) comprisesthe nozzle sleeve 2, the nozzle tip 3, and the nozzle body 4 whichprovides the air inlet 5 (the only inlet for air under pressure) and oilinlet 6. The nozzle is mounted in the burner by its threads 7 beingscrewed into the threaded collar 8 of the nozzle holderand-spacer 9.Generally, all secondary air is drawn into the burner by the current ofgases passing through the burner, initiated by the primary airintroduced through inlet 5. The volume of the gases increases as theypass through the burner due to their being heated and the partialcombustion which takes place within the burner.

The nozzle is assembled by slipping a metering insert 10 or 10' (FIGURES,9-11) or the like, with a suitable opening 11 or 11' or the like, intothe sleeve. The size of the opening controls the amount of oil aspiratedinto the combustion chamber. The metering insert may be omittedaltogether to supply the maximum amount of oil. Thus, the amount of oilsupplied to the burner is established, and is not changed thereafterunless some change is made in the oil requirements. The washer 12 ofnylon or the like which is sufficiently resilient to prevent rattling,is first put into the bore of the body 4. The sleeve and insert are thenput in place and the tip is screwed into the body to hold the sleeve inplace.

The end 24 (FIGURE 7) of the sleeve which is nearest 7 and 8) in theouter surface of the nozzle, between the nozzle and the spacer 29(FIGURE 7) which abuts the body of the nozzle at the air inlet 5.

The aspirated oil passes out through the nozzle tip 3 into the burnerwhere the air diffusers 45 and 46 accelerate its whirling motion andform it into a conical spray. The spray passes through the electrodeassembly 48 and into contact with the inner screen 50 (FIGURE 2) in thecombustion chamber. There are two electrodes 52 and 53 within theelectrode assembly. 7

The combustion chamber 60 (FIGURES 1, 2, 5 and 6) is provided withidentical screen retainers 62 and 64 (FIGURES 2 and 5). The outer screen66 fits inside of the outer prongs 68 (FIGURES 5 and 6) of the screenretainers and the middle screen 7 fits inside of the inner prongs 72 ofthese retainers 62 and 64. The ring 74 (FIG- URES 2 and A) is welded toinner screen 59 before this screen is assembled in the burner. This ring74 is registered against the back retainer ring 7 6 (FIGURES 2, 5, 5Aand 6) and limits the extent to which this screen can be slid into theburner. The prongs 77 on ring 76 provide just room enough to accommodatethe screen 50 within them. Before assembly in the burner, these prongs77 are peened at 78 (FIGURE 5A) to cause them to become enmeshed in thescreen.

The front plate 80 is held by rivets 81 to narrow bracketjs 82 whichextend through the notches 84 (FIGURE 6) in the combustion chamber 61}and their inner ends are notched at 86 to abut against the burnerretainer screws 88. These screws extend through openings 90 in thenozzle holder and spacer 9; openings 93 and 94 in the air diffusers 45and 46; openings 95 and 96 in the gaskets 97 and 98; openings 99 in theporcelain housing 48 of the electrode assembly; openings 100 in thegasket 102; openings 104 in the back retainer ring 76; partial openings108 in the screen retainer 62; partial openings 110 in the screenretainer 64; openings 112 in the combustion chamber 60 and then throughopenings 114 in the back plate 116. They are held in place by the hexnuts 118 which are separated from the back plate by lock washers 120.

The electrical conductor 122 (FIGURES l and 3) is provided with anopening at one end through which one of the screws 88 (FIGURE 3) passes,and at the other end there is an opening in which the electrode 52 isheld by the nuts 126. The other electrode 53 passes out to the recess130 in the electrode housing 48 and it is here connected with theterminal 132. The electrodes are insulated from the metal housing. Theinner ends of the electrodes extend up into the path of the oil mist asshown in FIG- URE 3 and secondary air sucked through opening 134(FIGURES 1 and 2) diffuses the spark into the chamber. Alternatively,the inner ends of the electrodes may be located within the recess 135,and in that case the spark is drawn into the path of the oil mist by thecurrent of air drawn into the burner through the opening 134.

The diffusers 45 and 46 are identical. They are stamped from sheetmetal. There are three wings 140 on each of these air diffusers and theyextend in from the main portion of the diffuser as shown in FIGURES 2, 3and 6. These wings are cut from the center of the stamping, a part ofwhich is removed. In installing these diffusers which are identical, theouter annular portions are brought into flat contact, and are turned sothat the holes in the annular portions coincide and the wings of therespective diffusers are located between one another as best shown inFIGURE-3. As perhaps best shown in FIGURE 6, one portion of the, base ofeach wing is integral with the outer annular portion of the diffuser,and the other portion is cut away so that when the wings are angled outas shown in FIGURE 2 they impart a swirling conical motion to the airstream as it passes through them. This gives an additional swirlingmotion to the subsequent spray as it passes through the electrodeassembly and out through the screens.

The outer and inner prongs 68 and 72 on the identical screen retainers62 and 64 are bent in as best shown in FIGURE 6. These prongs are bentin at different distances from the center of each retainer, as clearlyshown in FIG- URE 5. The outer edges of the respective retainers areflanged toward one another, and they are notched at 141 to receive thebrackets 82 on the back plate (FIGURE 6). These notches coincide withthe notches 84 in the rim of the combustion chamber 60.

The drawings illustrate a new burner as it is received from themanufacturer. In each of the gaskets 97 and 98 there are but twoopenings 143 in addition to openings 94 and for the screws 88. These areon opposite sides of the gaskets. These openings 143 coincide withopenings in the other elements and are designed to channel a measuredamount of secondary air into the combustion chamber. When a burner isinstalled in a particular piece of equipment, such as a clothes drier orfurnace, etc., it will be known how much secondary air will be requiredfor the amount of oil it will utilize. If the two openings in eachgasket are not enough to supply the required secondary air, one or moreadditional holes are readily punched in all of the gasketssimultaneously by inserting a sharp implement into one or moreadditional openings provided in the stampings, etc., starting at theholder 9 and extending through the several elements until the implerne-nt has passed through the gasket 102. As explained, more or lessoil is supplied to the burner by proper seleetion of the insert 10 or10" or other insert. Thus the burner described is adapted to serve inequipment hav ing widely different calorie requirements or firingfates.- Any additional holes required in the gaskets are preferablydistributed uniformly about the edge of the burner, as the holesprovided in the metal stampings permit.

In operating the burner, secondary air is drawn into the burner throughthe openings (FIGURE 6) in the holder 9 to be mixed with the aspiratedoil immediately after it leaves the nozzle.

It is essential to introduce additional secondary air into thecombustion chamber 60 outside of the outer screen 66 (FIGURE 2). This issupplied through two or more of the holes, just described, which areprovided in the outer portion of each of the various elements, as bestshown in FIGURE 6. One such opening is indicated by the numeral 152 andarrow in FIGURE 2. This secondary air is mixed with oil mist in thespace around the outer screen 66 (see FIGURE 2) and returned as agasified mixture through the screen pattern to be mixed with the gaseswhich are carried through and out of the combustion chamber to asupplemental burner where the gases derived from the oil and air areburned. In order to provide this additional secondary air, coincidingopenings are provided in the various elements as best shown in FIGURES 2and 6. The number of such openings in each burner which are effectivefor the introduction of second ary air is limited to the number ofopenings provided in the several gaskets, as above described. The air isdrawn into the space in the outer portion of the combustion chamberthrough these openings by the current of the aspirated oil and gasespassing through the burner. Only enough air is supplied to the burner topartially oxidize the oil. Sufficient combustion takes place within theburner to raise the temperature of the screens to red or white heatproducing infra-red radiation. The inner screen 50 becomes the hottest.The openings 155 (FIG- URE 2) in it are present to provide an element ofback pressure desirable for easy, quiet starting. Because the airsupplied to the burner is sufficient to onlypartially burn the oil, thegases leaving the combustion chamber are called starved gases.

The oil drawn up into the nozzle leaves the tip 3 as a cone. It meetsair introduced through channels 28 and the oil and air are given aspiral, conical motion as they pass through diffusers 140. Thecombustion chamber 60 is so located that the conical spray contacts theinner screen 50 within the combustion chamber. Much of the outer portionof the cone of the oil mist passes throu h "the inner scr en and somepasses through the middle screen and also some thr ugh the other screen.It is driven outwardly by the spiraled conical How of the air and oilmixture. It moves outwardly through that portion of the screens nearestthe back plate 116 anti then circulates back and is returned through theforward portions of the various screens 'in the general location of thecombustioh chamber adjacent the back retainer ring 106. The interceptionof the spiral spray by the screens produces intense agitation of thegases withinthe burner. As the ga'sified mixture passes back through theinner screen 50 it is mixed with the gaseous mixture flowing through theburner and is carried aloh'g'w'i'th it to the supplemental burner whereit is consumed. Thus there is a constant outhow of oil. mist outwardlyover the various hot screens and back. again throughthe screens withsecondary air which gasifies it. The oil is only partially burned. Theresulting gas is mixed with the general stream of the gaseous mixturewhich flows through the burner and out to the supplemental burner whereit is completely burned. In starting up the burner, the oil mist isignited and the temperature within the burner quickly rises and heatsthe screens. As the contents of the burner approach the final operatingtemperature, all (or substantially all) of the oil is transformed intogas within the combustion chamber by reaction with the air, and theresulting gases pass out of the burner to the supplemental burner whichmay be of any suitable construction.

Safety means, etc. are provided as required, the device in FIGURE 1identified by the numeral 160 being a flame sensor.

The invention is covered in the claims which follow. What we claimis: 1. An oil burner which includes: an oil inlet, a primary air inlet,means for producing a conical spray of the oil in the air and a passagefor the spray leading therefrom,

electrodes in the passage to ignite the oil in the spray,

screen means located so as to be contacted by the spray and heated toincandescence from partial combustion of the oil in the spray, saidscreen means surrounding the passage and separating it from a chamberexterior of the passage which is closed exteriorly of the screen meansexcept for an inlet for secondary air, and

means for conducting secondary air into said exterior chamber.

2. The burner of claim 1 in which:

the screen means is metallic and is arranged as a series of successivescreens through which the spray passes.

3. The burner of claim 1 in which the screen means includes means forpreheating the secondary air before it contacts the portion of thescreen means which defines the passage.

4. The burner of claim 1 in which there is a circumferential enlargementin the passage and the screen means is cylindrical and is over theentrance from the passage into the enlargement.

5. The burner of claim 4 in which several cylindrical metal screens inthe enlargement separate the passage from the means for introducingsecondary air into the burner.

6. The burner of claim 1 in which there are separate elements whichindividually comprise:

(1) the portion of the burner in which the oil inlet and primary airinlet are located,

(2) the electrodes, and

(3) the portion of the burner which contains the screen means, and

there are aligned openings in the margins of each of said elements,screws passing through some of the aligned open- '6 tags holding thedihere'nt elements together; and there is at least one passageway formedby additiohal aligned openings which forms at least one of said meansfor introducing secondary air into t r. '7. The burner of cl-aim 6 inwhich there is "a gasket between at least two of the elements, there isat ieast one less aligned opening in the gasket than in the otherelements and the gasket blocks a passage torsecondary air formed byaligned openings. 8. The burnei of claim 1 having in the portionadjacent a tor the entering air which is composed of identical partswith hat marginal 'polftions which are in contact with one another, withwings angling inw r cll away from said portions to impart a whirlingconical motion to theenterin-g air, the wings on one ai' ruse-r beinglocated between the wings on the other diffuser.

9. The hunter of elatin 7 in which marginal openings in the elements for(1) the screws and (2) the formation efpassa for secondary air around atleast a substantial portion of each element are evenly spaced, and thereis adjacent the inlets for oil and primary air a fd'iituser' for theentering air which is composed of identical parts with flat marginalportions with open in'gs in at least a portion of each marginal portionspaced the same as in the other elements, with diffuser wings anglingaway from the entrance into said passage for-the air to a whirlingconical motion to the entering spray, said openings and wings being sospaced that by passing the screws through openings in the respectivediffusers which are differently located with respect to the wings, thewings on the one diffuser are located between the wings on the otherdiffuser.

10. The burner of claim 1 which includes:

a nozzle in which the inlets for oil and primary air are located, andone end of the nozzle is held in one end of the wall that forms thepassage, and

this end of the nozzle is notched and passages exist between the notchesand wall for the introduction of secondary air.

11. The burner of claim 1 which includes a nozzle in which the oil inletis located:

an oil passage through the nozzle which is formed in a metering partremovable from the nozzle, and

parts of the nozzle are threaded for easy separation to gain access tosaid metering part.

12. The burner of claim 11 in which the removable part is a cylinderwith a groove in one surface, which part is adapted to slide in the oilpassage leading from the oil inlet.

13. The burner of claim 5 in which each of the several screens surroundsthe passage and these screens are sup ported in identical retainers ineach of which there is an opening large enough to prevent obstruction ofthe gases passing through the passage,

each retainer having concentric series of prongs projecting from onesurface,

the prongs of each series being adapted to position one of the screens.

14. The process of burning oil which comprises:

mixing the oil with air and forming a spray therefrom,

igniting and only partially burning the oil in the spray in a combustionzone, and

passing the burning mixture through screen means and thereby heating atleast a part of the screen means to a temperature at least thetemperature of red heat,

said mixture being confined after passage through the screen means, andadmitting secondary air thereto and mixing it therewith and therebyproducing a combustible gas from the mixture, and

passing this mixture through the screen at said temperature into saidcombustion zone.

15. The process of claim 14 in which said secondary air is heated bysaid screen means.

16. The process of claim 14 which comprises:

passing said combustible gas miXture from the combustion zone to acombustion chamber and there completely burning the combustible matterin the mixture.

17. An oil burner which comprises a combustion-chamher, an oil inlet anda primary air inlet, a nozzle adjacent to which said oil and air inletare connected and which is in one end of the chamber into which anoil-air mixture is sprayed by the nozzle, perforate partition meanswithin the chamber which separates a portion of the chamber throughwhich partition means some of said oil-air mix ture is admitted to thisportion and in burning raises the partition to incandescence, openingsfor introducing secondary air to the chamber and to said portion, therebeing no other opening in said portion, and ignition means for the oilbetween the nozzle and said partition.

18. The burner of claim 17 in which the partition means is cylindricaland separates an annular peripheral portion from the rest of thechamber.

19. The method of operating a burner which comprises 25 forming an oilspray with insuificient air for complete combustion of the oil,introducing the spray into one end of a combustion chamber one portionof which is separated from the remainder of the chamber by a perforateguide and igniting at least a portion of the mixture before 30 itreaches said guide, passing some of the spray with air through the guideand mixing it with secondary air in an amount insufficient for completecombustion of the combustible matter then present in the mixture withpartial combustion of said combustible matter to gases taking place insaid portion of the chamber separated by the guide.

20. The process of claim 19 which includes returning said combustiblematter, while burning, to the combustion chamber and mixing it therewith oil-air mixture, and passing the resulting incompletely burnedmixture out of the other end of the chamber to a combustion zone andburning it.

References Cited UNITED STATES PATENTS 329,844 11/1885 Mulloy 1581.51,355,443 10/1920 Auger 158-76 1,450,229 4/1923 Robinson 15873 2,869,6261/1951 Sherman 1584 3,124,193 3/1964 Klein 158-53 3,131,749 5/1964 Davis158-4 3,221,796 12/1965 Nesbitt 158-1.5

FOREIGN PATENTS 815,643 7/ 1959 Great Britain.

FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner.

1. AN OIL BURNER WHICH INCLUDES: AN OIL INLET, A PRIMARY AIR INLET,MEANS FO PRODUCING A CONICAL SPRAY OF THE OIL IN THE AIR AND A PASSAGEFOR THE SPRAY LEADING THEREFROM, ELECTRODES IN THE PASSAGE TO IGNITE THEOIL IN THE SPRAY, SCREEN MEANS LOCATED SO AS TO BE CONTACTED BY THESPRAY AND HEATED TO INCANDESCENCE FROM PARTIAL COMBUSTION OF THE OIL INTHE SPRAY, SAID SCREEN MEANS SURROUNDING THE PASSAGE AND SEPARATING ITFROM A CHAMBER EXTERIOR OF THE PASSAGE WHICH IS CLOSED EXTERIORLY OF THESCREEN MEANS EXCEPT FOR AN INLET FOR SECONDARY AIR, AND MEANS FORCONDUCTING SECONDARY AIR INTO SAID EXTERIOR CHAMBER.